Cleanup efforts are currently underway in four separate oil spills that have occurred in the last ten days.

On March 27th, a train carrying Canadian tar sands dilbit jumped the rails in rural Minnesota spilling an estimated 30,000 gallons of black gold onto the countryside.

Two days later a pipeline ruptured in the town of Mayflower, Arkansas, sending a river of Albertan tar sands crude gurgling down residential streets. And news is just breaking about a Shell oil spill that occurred the same day in Texas that dumped an estimated 700 barrels, including at least 60 barrels of oil into a waterway that leads to the Gulf of Mexico (stay tuned for more on that).

This week a Canadian Pacific freight train loaded with oil derailed, spilling its cargo over the Northwest Ontario countryside. Originally reported as a leak of 600 liters, the CBC reported on Thursday that the estimated volume of the spill has increased to 63,000 liters.

The accelerating expansion of Alberta’s tar sands has North America’s current pipeline infrastructure maxed out and, as a result, oil companies have been searching for an alternative way to move their product to market. As lobbying efforts around the stymied Keystone XL and Northern Gateway pipelines intensify, oil companies have been quietly loading their toxic cargo onto freight trains.

There has been a marked boost in the rail transport of crude in the last three years as new extraction techniques increase production in the tar sands. According to Reuters, “U.S. trains carried 233,800 carloads of crude oil in 2012, more than double the 65,800 carloads transported in 2011 and dwarfing the 29,600 in 2010, according to figures from the Association of American Railroads.”